1. Field of the Invention
The present invention relates to a method for producing medium-chain ω-hydroxy fatty acids, α,ω-dicarboxylic acids, and ω-amino fatty acids from long-chain fatty acids by biotransformation. More particularly, the present invention relates to a transformant which is transformed to express Baeyer-Villiger monooxygenase (BVMO), a method for producing C5-C14 medium-chain ω-hydroxy fatty acids, α,ω-dicarboxylic acids, ω-amino fatty acids, or alcohols from C16-C20 long-chain fatty acids by biotransformation using the transformant, a method for producing a fatty acid derivative having an ester group which is introduced into the chain thereof from keto fatty acid using the BVMO, and novel ω-hydroxy fatty acids which are prepared by the method.
2. Description of the Related Art
ω-hydroxy fatty acid is a fatty acid (HOCH2(CH2)nCOOH) with one hydroxyl group at the end of the fatty acid. It has been used as a monomer in the production of polyethylene-based plastics, and is widely used in the production of emulsifiers, adhesives, or coatings and in the preparation of cosmetics or medicines. ω-hydroxy fatty acid can be also used as a precursor in the synthesis of long-chain dicarboxylic acids which are widely used in the production of polyamide, polyester-based plastics, cosmetics and household items.
Medium-chain α,ω-dicarboxylic acid (HOOC(CH2)nCOOH) and ω-amino fatty acid (H2NCH2(CH)nCOOH) have been used as monomers in the production of plastics of polyamide, polyester, etc., and also used in the production of emulsifiers, antifreezes, paints, and coatings. Further, they have a variety of physiological activities such as antibacterial activity, etc., and thus are widely used in the production of cosmetics, foods, and household items. For example, annual production capacity of a C10 medium-chain dicarboxylic acid, sebacic acid ((HOOC)(CH2)8(COOH)) is over 50,000 MT, and it is used in the production of plastics, candles, cosmetics, emulsifiers, antifreezes, and corrosion inhibitors. Further, sebacic acid is used in the production of acne treatments or cosmetics, and household items owing to its antibacterial activity.
Such medium-chain ω-hydroxy fatty acid, α,ω-dicarboxylic acid, and ω-amino fatty acid are rarely found in nature, and thus are industrially produced by chemical synthesis. Chemical synthesis has problems of requiring high temperature and high pressure, strong acids and/or toxic oxides causing severe environmental problems (U.S. Pat. Nos. 5,952,517, 6,392,074, 5,420,316, and 20110105774). For example, sebacic acid is produced from ricinoleic acid by chemical cleavage (U.S. Pat. Nos. 5,952,517 and 6,392,074). However, chemical cleavage of ricinoleic acid requires a high temperature process at 200-300° C. or higher and use of strong acids such as sulfuric acid and use of toxic substances such as a heavy metal ion catalyst, an organic solvent, etc. Problematically, this process is dangerous and produces a large amount of environmental pollutants after production.
Azelaic acid, a C9 medium-chain dicarboxylic acid, is produced by ozonolysis of oleic acid (U.S. Pat. No. 5,420,316). However, the production of azelaic acid by the above technique requires the use of a strong oxidizer ozone, which produces various by-products. Therefore, a separation/purification process using a heavy metal catalyst is essential to remove the by-products produced thereof. Due to many other problems including the complex separation/purification process, environmental pollution, and excessive energy use, there has been a growing need to study solutions of the problems. Accordingly, there has been an active study focused on a simple and environmentally friendly production method, and the use of a biocatalytic process in the method. For example, a method of producing long-chain ω-hydroxy fatty acids from long-chain fatty acids using enzymes and a production method of medium-chain dicarboxylic acids from a petroleum compound hydrocarbon have been developed. However, a method of producing medium-chain ω-hydroxy fatty acids, α,ω-dicarboxylic acids, ω-amino fatty acids, or alcohols from renewable long-chain fatty acids using enzymes has not been developed yet.
The present inventors newly demonstrated that BVMO is able to convert keto fatty acids derived from C16 to C20 long-chain fatty acids into fatty acid derivatives having an ester group introduced into the chain thereof, which can be cleaved by ester hydrolase, and they found that medium-chain ω-hydroxy fatty acids, α,ω-dicarboxylic acids, ω-amino fatty acids, alcohols, etc. can be produced from long-chain fatty acids using a transformed microorganism introduced with the BVMO gene, thereby completing the present invention.